Hey Ralph there nice to have,,, you can buy them on the internet 50.00 ,,, I am going to get one here soon , and scale is nice to have as well ... i bought one for 15.00 on the net ,, guzz1
You can get a nice tester for under a $100. It will tell you if the diamond is real. Here is a link to an example. http://www.jewelrytelevision.com/index.aspx?tid=21847&Ntt=Diamond%20Tester&N=49%20&mcid=XSM01019306|Broad|diamond%20tester|Any&s_kwcid=diamond%20tester|908176566&cm_re=Results*1*1&cm_pos=1&bca=JLP596&ptid=7362&R=2445447&cm_sp=
This type test the resistance. you can get a UV light that gives a good indication of being a diamond.
All said however, I just go to a local jeweler and the will check my item for free, usually clean it a little and give a free general quote. The worth of a diamond varies with the "Cs". Check the internet for a complete diamond education.
I have a diamond tester. I find it very reliable. Mine will beep and gives off a green light on a diamond. Any false stone will make it go silent with no light. Mike.